ABSTRACT

It is well known that, for the time being, certain functional groups need a temporary inactivation of their intrinsic chemical properties in order to allow transformations elsewhere in a molecule. is inactivation is achieved by protecting groups, the use of which has been frequently reviewed, commented, and criticized.1,2 When the original reactivity of a functional group has to be restored, the protecting group needs to be removed by a reagent, which should be strong enough to induce the detachment of the protecting moiety, but mild enough to keep the rest of the molecule intact-including possibly other protecting groups that must be maintained for further transformations. is compatibility between dierent protecting groups, that is, the possibility of their selective removal in any given sequence, is oen called orthogonality, and this is highly desirable in order to give to the synthetic plan a certain exibility. However, the number of orthogonal sets of hydrolysis conditions is unfortunately rather small (e.g., acidic, basic, reductive, oxidizing, and nucleophilic conditions), and thus any additional dimension would be welcome.